Voice over Internet Protocol (Voice over IP, VoIP)

VOIP is a family of technologies, methodologies, communication protocols, and transmission techniques for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet. Other terms frequently encountered and often used synonymously with VoIP are IP telephony, Internet telephony, voice over broadband (VoBB), broadband telephony, and broadband phone.



Internet telephony refers to communications services—Voice, fax, SMS, and/or voice-messaging applications—that are transported via the Internet, rather than the public switched telephone network (PSTN).



How does VOIP Work?

 VoIP generally work on the established methods of sending packed digitized data over the internet. TCP/IP networks are made of IP packets containing a header (to control communication) and a payload to transport data: VoIP uses it to go across the network and come to destination. While sending information analog data is digitized with the help of an ADC (analog to digital converter), transmitted and then at the other end the data is again transformed in analog format with DAC (digital to analog converter) to use it. VoIP also works in very similar manner. VoIP digitalizes voice in data packets and then sends them to the destination and reconverting them back to voice at destination.

 VoIP is available on many smart phones and Internet devices so that users of portable devices that are not phones may place calls or send SMS text messages over 3G or Wi-Fi



Advantages

• The ability to transmit more than one telephone call over a single broadband connection.

• Because of the bandwidth efficiency and low costs that VoIP technology can provide, businesses are migrating from traditional copper-wire telephone systems to VoIP systems to reduce their monthly phone costs.

• Secure calls using standardized protocols (such as Secure Real-time Transport Protocol). Most of the difficulties of creating a secure telephone connection over traditional phone lines, such as digitizing and digital transmission, are already in place with VoIP. It is only necessary to encrypt and authenticate the existing data stream

• Probably one of the most compelling advantages of packet switching is that data networks already understand the technology. By migrating to this technology, telephone networks immediately gain the ability to communicate the way computers do.

References:

http://en.wikipedia.org/wiki/Voice_over_Internet_Protocol